A biorobotic pectoral fin was developed and used to study how the flexural rigidities of fin rays within a highly deformable fish fin affect the fin's propulsive forces. The design of the biorobotic fin was based on a detailed analysis of the pectoral fin of the bluegill sunfish (Lepomis macrochirus). The biorobotic fin was made to execute the kinematics used by the biological fin during steady...

(paper pages 133-156) zagros active fold-thrust belt lies on the northern margin of the arabian continental crust it is a young fold-thrust mountain belt currently shortening, thickening and uplifting as a result of the collision of the arabian and iranian plates. rethickening of crust during collisional orogenies could have been carried out by reversal of fault motion along the mesozoic normal...

The germination of seeds of Xanthium pensylvanicum Wallr. occurs in 2 phases, an initial passive phase of water uptake followed by an active phase of growth. These 2 phases have been separated experimentally, and shown to occur similarly in isolated cotyledons and embryonic axes. Measurements of the physical thrust generated by the entire seed and its separate components of cotyledon and axis r...

The fluid-structure coupling process of a plunging rigid airfoil with a thin elastic plate attached at the trailing-edge is simulated numerically by using unsteady potential flow source/vortex panel method and the Euler-Bernoulli beam vibration differential equation. The flow characteristics, the unsteady aerodynamic loads, especially the thrust effects of the plunging motion are computed. The ...

At constant average speed (v), a balance between thrust force (Ft) and drag force (Fd) should occur: Ft-Fd = 0; hence the power generated by thrust forces (Pt = Ft·v) should be equal to the power needed to overcome drag forces at that speed (Pd = Fd·v); the aim of this study was to measure Pt (tethered swims), to estimate Pd in active conditions (at sprint speed) and to compare these values. 10...

Escape locomotion of the common dock shrimp, Pandalus danae Stimpson, is the result of a rapid flexion of the abdomen that lasts approximately 30 ms. The hydrodynamic forces that result from this motion lead to body accelerations in excess of 100ms~ and body rotations of about 75°. We examined the mechanics and kinematics of this mode of locomotion with both experimental and theoretical approac...